Coring apparatus



1943- J. E. HOFFOSS E'IV'AL 2,331,553

CORING AiPARATUS Filed June 1 1942 Z 2: 2 277-; O/PA/k Patented Oct.12,1943 I UNITED STATES PATENT OFFICE coame mmrus John E. Hoil'oss andJohn C. Stokes, Houston, Tex., assignors to Reed Roller B Company,Houston, Tex a corporation of Texas Application June 1, 1942, Serial No.445,274 4 Claims. (Cl. 255-72) This invention relates in generalto'coring apparatus and more particularly has for its general object theprovision of a coring apparatus of the type known as a wireline coringappa ratus in which there will be embodied an improved holddownmechanism for the core barrel in combination with an improved mechanismfor driving the-core barrel or causing it to rotate with the core bit.

Another object of this invention is to provide a driving mechanism fordriving a wireline core barrel which mechanism will be entirely separateand independent from the means for holding the core barrel down.

Another object of this invention is to provide a driving mechanism for awireline core barrel which mechanism may be located adjacent the lowerend of the core barrel thus avoiding the necessity of transmittingtorque from the lower end of the core barrel to the upper end thereof.

Another object of this invention is to provide a driving mechanism for awireline core barrel which mechanism will be simple to construct, easyto install, and positive in its operation.

Another object of this invention is to provide a driving mechanism for awireline core barrel which mechanism will permit the downward passage ofthe core barrel until it seats in core taking position within the corebit, without necessity for the core barrel to rotate one way or theother in order to fit into the driving mechanism as it moves downward toits seat.

Other objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawing in which is set forth by way of illustration and example oneembodiment of this invention.

In the drawing:

Fig. 1 is a view partly in side elevation and partly in vertical crosssection illustrating the upper end of a core barrel having a holddownmechanism constructed in accordance with this invention.

Fig. 2 is a view in longitudinal cross section illustrating a corebarrel constructed in accordance with this invention in place within acore bit, with the driving mechanism for the core barrel in placetherein.

Fig. 3 is a longitudinal cross section showing a fragmentary portion ofthe structure illustrated in Fig. 1 and taken along the line 3-3 of Fig.1.

Fig. 4 is a transverse cross section taken along the line 4-4 of Fig. 1.

the wireline core barrel illustrated consists of an upper barrel Ihaving a fitting 2 welded at 3 or otherwise secured to the lower endthereof, and having a lower core barrel 4 threaded at 5 to the lower endof the fitting 2. The lower end of this lower core barrel is threaded toreceive the protruding cutter head 6. The cutter head 6 is formed with apart of its inner surface of larger diameter so as to receive the corecatcher structure 9. The core bit may be of any conventional form and inthis instance is shown as being of the drag type having blades E.

On its upper end, the upper core barrel carries a fitting H which may bewelded or otherwise secured thereto as shown at l2, and threaded on tothis fitting is the valve cage l3 having a ball valve I4 disposedtherein. The ball valve I4 is adapted to seat upon a valve seat I5 heldin place by means of a nut l6 or the like. The valve cage I3 is providedwith lateral openings I! so that fluid may fiow upwardly from within thecore barrel past the ball valve. l4 and out through the openings H. Nofiow can take place inwardly through the openings l1 and into the corebarrel, however, because of the action of the ball valve l4 which actsas a check valve. The valve cage l3 has a part integral therewith whichextends upwardly and is provided with a through slot l8 adapted toreceive the holddown shoes l9 and 20 which fit side by side within theslot l8 and have gripping teeth 2| extending in opposite directionsoutwardly from the body of the valve cage. Each of these shoes l9 and 20has a slot 22 extending at an angle to its gripping surface adjacent itslowerend and a slot 23 of similar size and angle but extending in theopposite angular direction with respect to the gripping face of the dog.

The upward extension of the valve cage I3 is also provided with alongitudinal bore adapted to receive a plunger 24 the lower end of whichis bifurcated to straddle the upper portions of the dogs 20 and 2 I, asshown at 25. This plunger 24 is normally urged in an upward direction bymeans of a spring 26 that surrounds the plunger above the upper end ofthe body I 3 and bears at itsjupper end against the enlargement 21 onthe plunger 24. The upper end of the plunger 24 may be provided with aspear head 28 adapted tobe engaged by an overshot of the typecustomarily employed for removing wireline core barrels from drillstems.

Extending through each of the two lower slots 22 in the respective dogsI! and and having its opposite ends anchored in the body i3 is a pin 29.A similar pin 30 extends through the slots 23 in the two shoes I9 and 20and has its opposite ends anchored as shown at 3| in the bifurcatedlower portion of the plunger 24.

It will readily be seen that the plunger 24 is normally urged in anupward direction by the spring 26 and when in its upper position theplunger will hold the pin 30 in an upward position with respect to theslots 23 and thus move the upper ends of the shoes or dogs I! and 20inwardly to disengage the teeth 2| from the inner surface of the drillcollar or other portion of the drill stem. At the same time, this upwardmovement of the plunger will cause an upward movement of both of theshoes I! and 20 with respect to the pin 29, and this will serve toretract the lower ends of these shoes from their frictional engagementwith the drill collar or the like. On the other hand, it is contemplatedthat when slush is pumped downwardly through the drill stem it willimpinge upon the enlargement 21 on the plunger 24 and force this plungerdownwardly so as to move the pin 30 downwardly and so as to move theshoes I! and 20 downwardly with respect to the pin 29 so that the teeth2| on both of these shoes will be moved outwardly so as to provide africtional engagement between these shoes and the inner wall of thedrill collar. The core barrel will thus be frictionally held down duringthe taking of a core.

Referring again to the lower core barrel, the same is provided withmilled slots or grooves forming a splined arrangement at an intermediateportion thereof. This is clearly illustrated by the numeral 32.

Threadedly connected to the upper end of the drill bit 8 is a fitting33, this fitting being additionally internally threaded at its lower endto receive a nut ll. This nut 30 has grooves formed in its outer surfacefor the purpose of receiving the end portions 35 of the driving springs36. It will be noted that the end portions 35 have their upper ends 31turned inwardly and fitting into proper cut away portions of the nut 3|.These springs are bent around the lower end of the nut and have anupwardly and inwardly inclined portion 38 joined to the main drivingportion 36 which extends directly upwardly, and the upper end of thismain driving portion 36 has an upwardly and outwardly inclined portion39.

It will readily be seen that when the core barrel just described isdropped into place, its lower end will come in contact with the upperoutupon, the core barrel will be locked against rotation with respect tothe core drill and the core may be taken while the core barrel is heldagainst rotation with respect to the core drill.

It will be understood that while this invention has been described inconnection with a core barrel having a protruding cutter'head on itslower end, it may be used as well in connection with a barrel adapted toseat in-a core bit, the bit itself carrying the teeth which cut thecore.

It will be appreciated that a means has been provided for carrying outand accomplishing all of the advantages sought by this invention.

Having described our invention, we claim:

1. In a wireline coring apparatus, a drill stem, a core drill thereon, acore barrel adapted to be lowered into the drill stem and core drill,means on the core barrel adapted to expand and frictionally engage theinner surface of the drill stem to hold the core barrel against upwardmovement therein, splines formed on the core barrel, and resilient meanscarried by the drill stem and adapted to engage said splines to hold thecore barrel against rotation with respect to the drill stem.

2. In a wireline coring apparatus, a drill stem including 'a tubularmember, a core drill on said 1 drill stem, a core barrel comprising asecond tubuwardly inclined portions 3! of the driving springs bit I, ifthe driving springs I. are not already seated within the splines 32 onthe lower core barrel, the core barrel may rotate slightly with respectto the core drill untilsuch time as the springs I do engage with thesaid splines. Therelar member adapted to be lowered into the drill stemand core drill, means on one of said tubular members adapted to move ina radial direction to frictionally engage the surface of the other ofsaid tubular members to hold the core barrel against upward movementwithin the drill stem, splines formed on one of said tubular members,and resilient means carried by the other of said tubular members andadapted to engage said splines to hold the core barrel against rotationwith respect to the drill stem.

3. In a wireline coring apparatus, a drill stem, a core. drill thereon,a core barrel adapted to be lowered into the drill stem and core drill,splines formed on the core barrel, and a leaf spring extending in alongitudinal direction with respect to the core barrel along the innersurface of the drill stem and having an intermediate portion spaced fromthe interior of the drill stem, the end portions of said spring havingtheir inner surfaces inclined outwardly so that the core barrel may passdownwardly past the spring and cause it to flex outwardly except whensaid spring engages one of said splines, whereby said spring may engageone of said splines to hold the core barrel against rotation withrespect to the drill stem.

4. In a wireline coring apparatus, a drill stem, a core drill thereon, acore barrel adapted to be lowered into the drill stem and core drill,splines formed on the core barrel, an annular member carried'within saiddrill stem, and a spring key carried by said annular member and having aportion disposed between said annular member and the inner surface ofthe drill stem, and another portion extending through said annularmember to engage one of said splines, said last mentioned portion beinginclined away from the central portion of the drill stem adjacent itstwo opposite ends.

JOHN E. HOFFOSS. JOHN C. STOKES.

